title: Phospholipids and their fatty acids in infective juveniles of entomopathogenic steinernematid nematodes.
abstract: The composition of phospholipids and their fatty acids was investigated in the infective juveniles (IJs) of four species of entomopathogenic nematodes: Steinernema carpocapsae (strain All), S. riobravis (strain Biosys 355), S. feltiae (strain UK76) and S. glaseri (strain NC). In newly emerged IJs of the four species, phospholipids comprised 15-18% dry weight of the total lipids (or 5-6% dry weight of the nematode), and phosphatidylethanolamine and phosphatidylcholine constituted about 40 and 30%, respectively, of the total phospholipids, with phosphatidylserine (PS) and phosphatidylinositol (PI) collectively accounting for about 25%. Qualitatively, the four species had identical total phospholipid (combined non-acidic and acidic fractions) fatty acid profiles, although there were some differences in the relative proportions (mol%) of specific fatty acids. The fatty acid composition of the total phospholipids in newly emerged IJs was dominated by C16 fatty acids, specifically C16:0 (14-18%), C16:1n-7 (up to 20%) and C16:4 (up to 26%), whereas the major C18 fatty acid was C18:1n-9 (20-23%). Polyunsaturated C20 fatty acids collectively made up 8-13% of the total composition. When newly emerged IJs were stored in distilled water at 25 degrees C, the proportions of C16:0 and C16:4 decreased with storage time, whereas C16:3n-3 increased (by 30-fold in S. glaseri). These changes were mostly observed in the acidic phospholipid fraction (mainly PI and PS). No evidence was found for a correlation between the fatty acid composition of the phospholipids and the relative ability of the IJs of the four Steinernema species to survive desiccation stress.
authors.affiliation: Department of Biology, Imperial College of Science, Technology and Medicine, Ascot, Berkshire, U.K. m.n.patel@bio.ic.ac.uk
authors.forename: M N
authors.initials: MN
authors.lastname: Patel
authors.forename: D J
authors.initials: DJ
authors.lastname: Wright
mesh_terms: D000818:Animals; D003890:Desiccation; D005227:Fatty Acids / Q000032:analysis*; D010743:Phospholipids / Q000032:analysis / Q000737:chemistry*; D017172:Rhabditoidea / Q000254:growth & development / Q000502:physiology*
chemical_list: D005227:Fatty Acids; D010743:Phospholipids